The numbers lead Roberts to conclude that we need to engage in a process of global economic contraction. Once he works through that math, he'll find his choices are (a) to keep poor people poor and make rich people poor, or (b) to focus on technological innovation to accelerate the decarbonization of economic activity. Where ever he comes out on that debate, (a) isn't going to happen -- iron law and all that.

But seriously, kudos to David for taking the time to run the numbers and report the results -- we all benefit from such analyses, uncomfortable as the results might be.

Then there is the question of adaptation (my take is that emissions will grow until 2030 when China is starting to run out of coal).

The fact is that wealthy countries are much better able to lessen the impacts of warming. Mitigation and adaptation policies require money. So, if we keep the poor countries poor, we also rob them a chance to improve their lot. The same actually goes also for developed countries.

Not only is degrowth (or zero growth) politically untenable, but it's suicidal in the long run. Advances in science and technology require a growing economic base (which in turn requires advances in S&T); without continued innovation, new resources become impossible to unlock and any form of technical civilization becomes impossible to sustain.

Non-technical societies are far more vulnerable to natural and human disasters and extinction becomes inevitable. Roberts would have us choose assured extinction to avoid a remotely possible extinction.